【摘要】 利用地震反射结构、沟谷展布特征及岩石碎屑中轻—重矿物组合类型等研究成果,探讨了白音查干凹陷缓坡带西部下白垩统多物源模式。研究结果表明:白音查干凹陷缓坡带下白垩统地震相呈东西分带的特点,西部和东部发育前积反射,中部反射振幅相对较弱;西部物源充足,扇体规模相对较大。砂岩中的重矿物组合及碎屑组份在平面上差异性明显,南部以岩屑砂岩为主,西部、东部为长石岩屑砂岩;西部岩屑以花岗片麻岩为主,东部以片岩等变质岩岩屑占优势,南部含碳酸盐内碎屑等。缓坡带西部存在3个方向的物源,分别是沿盆地长轴方向的西部物源、短轴的南部物源和东南部物源。在盆地演化的早期短轴物源占主导,中后期长轴物源影响较大。更多还原

【Abstract】 Based on the seismic reflection,features of palaeogeomorphology and distribution of valley as well asthe combination types of light-heavy mineral in rock fragment,the direction and pattern of multi-provenance ofthe lower Cretaceous in the western gentle slope belt,Baiyinchagan Depression have been studied. The researchshows that seismic facies of lower Cretaceous in Xilinhaolai area,gentle slope belt of Baiyinchagan depression canbe divided into three types. The west east is dominated by the oblique crossing propagational reflections,whilereflection amplitude in the middle region is weaker comparatively. Provenance in the west is abundant and thus thefan scale is larger relatively. Both the heavy mineral combinations and debris components of sandstone in differentarea are different. Sandstone in the south is dominated by lithic sandstone,while the west and the east are dominatedby feldspar lithic sandstone;lithic of the western sandstone is mainly granite gneiss,while the eastern one is mainlymetamorphic lithic such as schist,yet the southern one contains intracoastal such as ooid,carbonate and so on. It isbelieved that there are three provenances in the western gentle slope belt including the western one along the longaxis,the southern one along the short axis and the eastern one. The short axis provenance prevails in the early timeof the basin evolution,yet it changes to be the long axis provenance in the middle and late time.更多还原